Residue Harvest Effects on Response to Applied Nitrogen and Corn Yield.

Corn residue harvest is common in Nebraska, primarily for feeding of beef cattle. Applied N immobilization is expected to be less with residue harvest due to reduced microbial activity for digestion of high CN organic material. Residue reduction may affect subsequent crop yield and response to applied N. Field research was conducted at three irrigated locations over two years in eastern Nebraska to determine if the economically optimal N rate (EONR) is less with >75% residue removed compared to no residue removal. All had deep silt loam or silty clay loam soil of good water infiltration and holding capacity. Above ground biomass N content, applied N recovery efficiency, and grain yield were 22, 43, and 20.3% higher with >75% residue removal compared with no residue removal. Agronomic efficiency of applied N use was not consistently affected. The effect on EONR was not consistent over site-years, and the results indicate a mean reduction in EONR with residue removal was between 10 to 20 kg ha-1.While removal of some corn residue is expected to result in higher yield of the following corn crop, N application rate should not be much changed.